In the early part of a last century, earthquakes caused severe damage to pipes, cables, ducts, and communication lines normally suspended within a building or the like. The suspended units would adversely sway with regard to the movement of the building which would remain intact. Such suspended devices moved independently and would break away from their installed positions creating severe damage requiring replacement in the existing building at great cost.
In order to fix the ducts, pipes, cables and other lines so that they would move in sync with the building when it vibrated under a seismic event, tie downs, hold downs, brackets, clamps, seismic anchors or fittings were developed to keep these elements intact during an earthquake. The fittings were designed primarily to reduce breakaway from the installed positions of the various suspended elements. Similarly, anchors were developed to keep machines and computer equipment from shifting on the floor to which they were positioned. Equipment hold downs are shown in U.S. Pat. No. 6,059,251 to Gutelius et al. and U.S. Pat. No. 5,699,993 to Hill.
The suspended elements supported by seismic bracing are shown in such patents as Biggane U.S. Pat. No. 4,065,218, Roth U.S. Pat. No. 5,118,317, and Thompson U.S. Pat. Nos. 6,050,035 and 6,247,274.
Other patents showing various similar devices include Hurtubise U.S. Pat. No. 4,524,936 and MacKarvich U.S. Pat. No. 6,176,056.
The devices shown in the patents referred to, limit deflection and reduce earthquake related damage, but do not solve the problems in that there tends to be rotation of the anchor mechanism to the channel support whether it be in the ceiling or in the floor which in turn causes unattended shifting of the fittings about an axis causing damage under more sever earthquakes even though the building structure itself may not be severely damaged.